This kind of fishing reel is well-known as the double bearing reel, which has the clutch and a clutch operating mechanism, the clutch being disengaged thereby to permit free rotation of the spool for casting, and engaging to transmit a driving force from the handle to the spool shaft through the clutch and drive mechanism, thereby permitting the winding up of the line onto the spool.
The drive mechanism comprises a handle shaft having a handle, a main gear supported rotatably to the handle shaft, a drag mechanism for transmitting a driving force from the handle shaft to the main gear, and a pinion engaging normally with the main gear. When the fishing line which is wound onto the spool by the handle through the engaged clutch, is subjected to tension overcoming the rotational resistance set in the drag mechanism, the spool and spool shaft rotate relative to the handle and handle shaft by virtue of a slip of the drag mechanism, thereby preventing the line from being subject to a load exceeding its break point.
In this case, the handle and handle shaft are idle, or the spool and spool shaft rotate reversely with respect to the handle shaft to thereby draw the line out of the spool.
When an angler releases his hold of the handle during the reverse rotation of spool, the handle and handle shaft rotate reversely following the spool, whereby the spool is free from the rotational resistance imported by the drag mechanism, resulting in that the line is drawn excessively from the spool.
Therefore, a stopper gear and a stopper engageable therewith have hitherto been provided at the handle shaft and frame respectively to prevent the reverse rotation of the handle shaft so that even when the line is subjected to a larger tension, an angler can release his hold of the handle.
Such an anti-reverse rotation mechanism, which provides the stopper gear on the handle shaft, can prevent reverse rotation thereof but not of the spool and spool shaft.
The reverse rotation of spool shaft can be impeded to a certain extent by increasing the rotational resistance set in the drag mechanism, which is limited so that the rotational resistance, even when adjusted to a maximum, cannot completely prevent the reverse rotation of the spool shaft. Hence, the spool slidably reversely rotates to draw out permit the line to be drawn therefrom by virtue of the action of the drag mechanism, thereby creating a problem in that the angler, even when intending to hook a big fish in a stroke, cannot do so.